Is it possible to perform a lossless rotation on a JPEG Image in PHP?

Question

I need to rotate some existing JPG images. They have already lost some detail, but I now want to rotate them and lose no further detail.

With a little research, it seems the only lossless Image rotation library for PHP is by using the jPegTran library.

Are there any other options when it somes to doing lossless jpg rotation?

Thanks!

Answer 1

Would't it be possible to call an external program say losslessrotator by exec('commandline');

Another option would be jpegtran by jpegclub

Answer 2

Couldn't you read the bytes and just do a transformation that would move them into the right position to rotate them?

Answer 3

JPEG is a lossy format, so the answer is no, you can't create a lossless rotate of JPEG on any application, programming language, or guru meditation.

What you can do, however, is minimize image data loss by using the $quality argument when saving the rotated JPEG, if you're saving it in JPEG format that is. If you're saving it in lossless format, then you've already minimized image data loss.

Example:

$img = imagecreatefromjpeg($file);
$rot = imagerotate($img, 90, 0);
imagejpeg($rot, $output, 100); /* set quality to 100% */